The assessment of auditory function is essential for any study that analyzes or manipulates the auditory system in relation to genetics, homeostasis, protection, or restoration of hearing. The Auditory Physiology Core will provide this critical support. While the auditory brainstem response will be the primary measure of auditory sensitivity, physiology facilities and expertise will be available for more in-depth measures of auditory function, e.g..otoacoustic emissions, efferent reflex, round window noise, cochlear microphonics, cochlear whole-nerve action potentials, and endolymphatic potential. Two new services include "hands on" training in state-of-the-art methods and procedures for multi-channel cellular recordings and patch-clamp electrophysiology. The Auditory Physiology Core will also coordinate noise exposures of animals with respect to each investigator's needs for either temporary or permanent threshold shifts. The availability of physiological measurements will aid individual projects but also promote collaboration among investigators with widely varying expertise but with similar questions pertaining to auditory physiology. Together with the Cell /Molecular Core, this core will provide the essential link of genetic, molecular and biochemical data to auditory structure and function. The core will also work closely with the new Delivery Core D. The studies fostered by this new core will require physiological assessment to evaluate the success of the interventions. The results obtained from the procedures described in this core will be analyzed for statistical significance with the assistance of the Statistics Department at the University of Michigan. To promote efficient and successful Core operation, regularly scheduled meetings will discuss progress in research, emerging techniques and future directions. Furthermore, the Core will continue to offer resources to replace current animal models (such as the guinea pig) with mice which offer marked advantages by virtue of increasing availability of molecular and genetic information. Procedures are in place for scheduling and prioritization of services and quality control, and to coordinate the activities of the Cell/Molecular and Auditory Physiology Cores to facilitate an increased understanding of the molecular and genetic basis for hearing function.